okay. so.

wtf is that other clutch switch on the pedal for?



when the clutch is pressed in enough to trip the switch, the cars idle bounces around 1500.



when the clutch is out and the switch isnt tripped, the engine shakes and the idle slowly drops to around 1000.



and this doesnt make any sense to me. any one have any ideas?



the tps is adjusted perfect. The idle a/f screw does nothing. The idle screw is tightened all the way down, and unscrewing it any doesnt really do anything.

i'm assuming its a vacuum leak making it bounce but i cant find it. besides that the clutch switch thing changing the idle is completely confusing me.

one is for the neutral safey switch and the other one not so sure,,,,,,,,, the switch wich gets tripped when the pedal is all the way to the floor is the neutral switch. and why it has any affect on your idle could be a ground fault or that much of a serious air leak. do the good ol times trick of brake cleaner and spray the intake down and see if you can find the leak. also make sure your maf is not stuck open



randy

its not the neutral switch, its the other one. and its the switch causing the idle change because when i crawl under there and push it in myself it changes. and when its unlugged it idles all shakey like it would without me touching the clutch.



i tried moving the afm around to make sure it just wasnt at the wrong angle, no luck.

i'll try brake cleaner tomorrow. i've tried starting spray but can never find one that actually works right.

one is the starter interlock switch, lets the car crank or not, obviously.



other is the clutch switch. Goes to terminal 1Q on the ECU. Page Z-32 and Z-34 in the wiring schematic book. Page F2-84 in the FSM, also F2-77 (unless it's n/a, then it should be F1-84 and F1-77).



With clutch released, KOEO, should see 12v at pin 1Q.

Clutch depressed, KOEO, should see below 2v at 1Q.



It's simply a wire from the PCM (1Q), to the switch, then from the switch to ground. the wire from the PCM is shared with part of the cruise control wiring.



Other then that i really dont think the switch does anything, just lets the car know when the clutch is pushed in and out.



do you still have a BAC? what exact idle controls do you have left? this is why i strip all my 7's down to only 2 adjusters (well three if you count the throttle cable).



the "neutral switch" is on the trans. damn lee if you just lived close to me id have your car running smoothly, idle is my specialty lol, i had a blown motor idling nicely lol.



kevin.

yeah im back to NA. although the car never idled right when it was turbo either.



ive had three 88 fc's and two different motors in this particular one. i have never been able to get one to idle normal. its so frustrating.



i still have a bac and all emissions. trying to get some money scraped up for a header then do complete emissions removal. stupid one piece exhaust with a cat.



i wanna to a megasquirt and tii intake manifolds on NA, but im broker then broke.



so the switch doesnt really do anything important, but its affecting the idle which is confusing as ****.

You shouldnt be idling around 1500 anyway.

Bring the engine to a steady 750ish, and get your idle controls right or remove them. Then you can retune or replace that tps.

yes i figure theres a vacuum leak causing the high idle. but the switch thing is completely throwing me off.

i emptied a can of flammible brake cleaner into the engine bay.



didnt find oooone leak.



if i pulled a vac line off and spray the cleaner into it the idle jumped up like it should.



but even resorting to completely spray bombing every bit of vacuum line and flange on the engine in mass amounts didnt cause one jump in idle.



could the bac coolant lines being kinda shitty make it jump?



im out of ideas here.

For the longest time with my fc, i couldnt get it to idle down below 1100 rpm, no matter what i did with the TB. Even without the BAC or any of the emissions stuff, it was the same deal. But it was prone to stalling if you abruptly let off the gas. But after bypassing that switch(which was bad upon inspection), I had to raise my base idle to get it to the 750-800 rpm it should be at. And my stalling issue went away completely. I believe that switch triggers a change in the ignition timing and/or fuel at idle. But for what purpose, I dont really know. I snipped the wires before the plug, and soldered them together, and forgot about it.

mines being the opposite though.



if i wired the switch up like you did, it would idle bouncing around 1500.



if i unplugged it and didnt wire it up, it would be at 1000ish motor shakin town.

Wire it like I did so its at 1500 rpm, then adjust the idle down with the idle screw on the tb, and then the throttle stop adjuster if you need to.

if i wire it, itll bounce all around 1500. and bounce around 2k when its cold.



the throttle screw is all the way in, and its still doing this.



and i cant find a vacuum leak anywhere.

Vacuum leaks dont cause high idle in mass air equipped cars, just makes for a shitty idle, or it wont hold an idle at all if its a bad leak.



The hunting idle is from the idle mixture being too lean. On S4's, you have the idle mixture screw which may help it some. I always had S5's so I never got to see how much that could really help it. But you have to get the idle down below 1k rpm, or you wont be able to get it smooth on the stock ecu. The throttle stops are adjustable, its a set screw with a lock nut. I removed the secondary one completely, so the plates would close completely. On the primary, loosen the lock nut, and back the set screw out until the idle gets to where you want it, then tighten up the lock nut. If that isnt enough adjustment, as was the case with mine, put a drop of epoxy over the bleed hole in the primary throttle plate.

mixture screw doesnt make any change.



wouldnt a vacuum leak cause the idle to jump as it makes a lean condition?

Thats a TPS issue, but you cant set it til you bring the idle down. Check the dashpot, they stick sometimes.

A vacuum leak would cause the idle to be lean, because the engine will be taking in air not accounted for by the AFM. On a speed density EMS, the ecu will read the decrease in manifold vacuum and compensate with more fuel, resulting in a high idle. In mass air equipped cars, the afm tells the ecu there is less air coming in that there actually is, resulting in a lean condition. Being lean will not result in a high idle unless it was overly rich to begin with. Mass air cars usually wont hold an idle with a vacuum leak, or if they do, it will be low and unstable.



Adjusting the tps will fix the hunting idle, provided you dont have a very agressive port. On my big SP, i couldnt get a smooth idle on the stock ecu regardless of setting the tps or anything. After putting on the MS, I had to make the idle way rich to smooth it out because of the agressive porting. But to set the tps properly, the idle has to be down below 1000 rpm. Focus on that first. Pull the TB and clean it if it hasnt been done. Its also a lot easier to get to the throttle stops with the tb off.

lee i had had that same problem with mine, i couldnt fix the bouncing idle for nothin, so i just said **** it!!!!! https://www.nopistons.com/forums/pub...O_DIR#>/ar.gif it was fine when i was driving. but when i stopped at annoyed everyone who was stopped around me, but they can kiss my ass.

Your car should be taken from you...

so lee you're saying the throttle stop screws are all the way backed out and it still wont go under 1500rpms?



try taking off everything before the afm, then block the inlet part of the afm, see if the car's idle falls.



if not you definitely have something leaking somewhere.



there's no reason with the throttle plates absolutely completely closed that the car would be idling at 1500.



unless the plates are gummed up and not really closed all the way, or someone drilled out the bypass hole in the primary plate to allow for more air.



double check the throttle body....and dont worry about setting the tps until you get it to idle under 1k, adjusting it while its over 1k is actually just messing up the tps setting.



kevin.

throttle stop?



is there an adjustment like the TII TB that adjusts where the wheel the cable goes on stops at? cause if so i havent touched that. i'll take a look tonight.

the screw on top of the tb for the idle speed is tightened all the way in if that is what you're referring to.



i'll try taking the filter and adapter off and block it with my hand.



i sooo want a real header and to get rid of eveyr emissions piece and megasquirt the bitch, but im broke as **** right now so im just trying to get what i have running right.



if it makes any difference, the car will randomly run good throughout the revs, and then randomly be kinda slow and stumbly and seems like its missing.

i think maybe the ports are sticking, or somethings just being dumb. or maybe its just it being really ******* cold outside.



shits so goddamn complicated.



i just want to know that my car is running 100% for once instead of always dealing with little problems that i cant figure out affecting how it drives and performs.



and ive been driving it forever with a random shitty idle. like today when its cold it bounces form 2k and up.

going through drivethroughs sucks, they cant hear me. shits just so annoying.

you dont need money to strip the thing, seriously there's very few things that arte on the motor that are actually needed, its always the first thing i do when i get a 7, i also never run a BAC...personally choice but i have good success with my methods, and ive fixed plenty of peoples "impossible" problems. If i still had my n/a i would've donated the exhaust system to you, but i sold the car for $600, you shoulda bought it from me, 30k on the motor and trans, 15k on the clutch. no one wanted it tho lol.







LOL welcome to the world of rotary, a 100% car is rare https://www.nopistons.com/forums/pub...IR#>/smile.gif.



also have you put a timing gun on the car? if the timing is off that'll make yuou rip your hair out trying to set the idle, been there with jw's car, his timing wound up being off almost 180 degrees and i still had that thing idling pretty solid at 1k, reset the timing and got it dead on and i had it idling perfectly https://www.nopistons.com/forums/pub...IR#>/smile.gif.



and rememebr, dont worry about the tps until you get the idle down to at least staying around 1k, then set the tps, then lower the idle some more, and then set the tps, and keep going like that until you get it where you want it and where its best, every time you move one of the idle adjustments (throttle stop, idle adjuster, etc) i always recommend at least double checking if not completely resetting the tps. and use the ohmmeter method, the lights thing is so-so.



kevin.

i shouldve never traded off my rb downpipe and presilencer.



now ims tuck with this h orrible one piece exhaust with a cat and i cant gut the emissions **** like i want to.



i couldnt find a throttle stop, but ill look harder.



its so goddamn cold i dont have the effort to **** with it.

i found the throttle stop on a spare na tb i had laying around.



**** looks impossible to get to with the tb still in the car.



i looked around at other ****, and it seemed like the dashpot was holding it open some, so i ripped it out.



ill see if that helped at all tomorrow.



i really need to find a tstat and put it back in.

i took mine out trying to diagnose some coolant problems at the track int he middle of summer and it never made its way back in.

and now with this weather its killing me.

nope, still idles wherever the hell it wants to.



idle with the clutch out is at 1500 solid now though for no reason at all.



and i think my exhaust is falling apart. car seems louder..

yea i thought i rmemebered the stop screw on the n/a's being hard to get too.



kevin.

seems impossible.



plus theres like **** covering up the nut, so its never been touched before.

betcha it fixes your problem then.



p.s. sell your car and buy a t2.



kevin.

i'd love to.



but i doubt anyone wants a busted up drift slut.



maybe ill boost it again...



haha, yeah right. like i have the money for that.

swapped ecu's for fun.



idle was at like 2k+ and bouncing.



now seems to be 1500 and bouncing.



or its just my imagination that it actually made a difference.



i hate this thing.



i wish it ran right.

i cant get to that screw and i highly doubt having the idle adjusted high would make it bounce like it does....



it also stumbles a lot in high rpms when im going WOT.



it all doesnt make sense and i have no idea which part of this fucked up 80's ECU idle control bullshit system im overlooking.

The high idle is enough to get the engine out of the "idle zone" on the map, so no matter how well everything else is working, you wont be able to hold a good idle at 1500 rpm. It has to be below 1k rpm to adjust the tps to where it will idle right. And setting the idle will affect the tps reading, so you need to lower the idle, set the tps, and then adjust the idle again if necessary, and the tps agsin if necessary. Its a pain in the ass, but its the only way Ive found to be really effective at getting a good idle.



As for the other, it could be a lot of things. I would check the fuel system first though. Fuel filter, injectors, etc.

lee, you need to adjust that screw.



the idle will bounce when its at 1500rpms because you dont have a good setting on the tps because its not in the idle zone.



you dont have to listen, but if you dont listen youre not allowed to complain.



kevin.

yeah yeah i knew that was whiney and someone was gonna say something.



today bombing home from my gf's house, it seemed like if the clutch was down enough to trip that switch the stumbling went away, but that could also be my imagination as its intermittent.



im tracking down a header/presilencer so i can tear everything off this motor and start fresh with no emissions and new gaskets, just to make sure.



ill see if i cant pull the uim off and adjust that screw some, slap it back together, and see if it helps at all. although that seems like a lot of work for a hit or miss idle screw adjustment.



another question, uim gasket. its paper. and its all there. ive taking the uim off and back on a few times. think its holding up? would rtv be okay to add in the mix to make sure? or do i need a new gasket?

Dont mean to rain on your parade but my 86 before it died did the same thing to me the engine was really shaky till one day it went POOF ! ! ! busted up side seal. do a compression check to be on the safe side you did say it was never the same after you boosted it maybe the boost took its toll

the boosted motor died. this is a new one.



i tore off the uim.



the throttle thing is nowhere close to even hitting the other adjustment screw teknics. its like a cm away from it.



upon further inspection, the primary throttle plate is not closed all the way when the throttle closed. and i cant push it closed anymore then it already is.



something in this mess of tb springs and plates is fucked i supposed.



so the tps thinks its closed but its really open slightly. might explain it.

before you pull the uim off to adjust that screw try a whole bunch of screwdrivers, i swear i was able to do it with it attached to the car, try a real long one or something.



damn i wish i lived near you lol i have a few ideas but its something i need to be able to look at in person before it would make sense.



kevin.

read the post above yours.



uim is off and the lever thats supposed to land on that screw stops way short of hitting it.



that and the primary throttle plate is open some with the throttle completely closed.

bac lines were pretty much dry.



so i figure the thermopellet **** never expanded.



so i took the screw out of that arm letting the throttle close all the way.



idles kinda shaky but pretty smooth at about 1k with the clutch in, and with it out, it dies.



but just like every time i take an injector out of a rail, i tore an o-ring so i got a bitchin fuel leak. and im all outta spares.



so im getting closer/

ghetto oring worked.



idles at about 7-800 with the clutch out in neutral.

with the clutch pushed in it drops a few hunded rpms but barely still stays running.



the clutch switch magically stopped affecting the idle.



and it cuts out reaaaaaal bad trying to go past 3k rpms.



it did this in the old car it was in. and if you unplugged the tps it would quit cutting out. and then randomly start cutting out again until i plugged the tps back in.

did this a few times and generally pissed me off. i think swapping tps's fixed it maybe? but when i put the uim back on i put on the cleanest looking tps i had.

maybe i'll swap back to the old one.



its too late to run it long enough to get the tps set and timing checked so i guess tomorrow hopefully setting the tps will get rid of the nasty cutout.

quadruple post yay



tps was set to 0v at idle. set it to 1v like it should be and it did the trick.



car idles great. amazing im so happy.



runs better too 99% of the time.



but if im going WOT, between 5 and 6k it cuts out reaaaal nasty. if i get past it it pulls like a bat out of hell.

doesnt seem to do it as much part throttle though.



any ideas?